The invention relates to a method for producing printed circuits by using basis material coated with copper, which basis material is drilled, purified, activated, possibly reduced in known manner and after-treated in known manner wherein the circuit diagram is applied, possibly after covering of the non-desired regions by a resist, through screen printing or photo printing.
Methods for producing printed circuits are already known, however they have certain disadvantages.
One disadvantage of the so-called subtractive technique is that large amounts of the coating of the basis material must be removed after the build-up of the conductor image. Simultaneously, the etching of the conductors leads to the known damages which are the more grave and percentage increase more rapidly the smaller the lanes are dimensioned or approached to each other, respectively. These phenomena thus contradict a further miniaturizing in the field of the subtractive technique.
A disadvantage of the so-called additive technique is the fact that the basis material must be coated with adhesives. After chemical treatment and activating, the adhesive is the basis for the selectively applied and chemically extracted copper and has clearly worse electrical characteristics in comparison with epoxy resin after the wet treatment, thereby limiting the dimension of miniaturized circuits.